[alsa-devel] Output to Input routing

[Vadim Lebedev]

Hello,

I remember reading AC97 specs that there si possibility to configure it
in such a way, that when doing stereo capture, left input channel will get
actual MIC input and  right input channel will get the copy of speaker output.
This setting is ideal for echo cancellation algorithm.
To my grand dismay i'm unable to find a doc of ALSA mixer API so i'm
unsucessuful  writing code to put mixer in such mode.  
Can some kind soul please contibuite a code snippet....


Thanks
Vadim